Mainly a destination for diners from its neighborhood, Gwynnett St. will draw a bigger clientele once word spreads about its food. (Gabi Porter (2))

Gwynnett St., a rewarding new modern-American bistro in East Williamsburg, is named for a street that no longer exists — what Lorimer Street, a block from the restaurant, was called 100 years ago. Might this confuse people?

“I’m sure it will,” owner Carl McCoy laughed. Gwynnett St. can puzzle in other ways, too. It’s a reservations-taking place with more Manhattan in its blood than many in Brooklyn; McCoy was once wine director at Esca, and executive chef Justin Hilbert worked at WD-50.

They stake out a border zone far from hipster Williamsburg’s heart. A few nights ago, Christmas lights still hanging a block away brought little cheer to a stretch less than bustling after dark.

But Gwynnett St. — a compact, cozy L mostly in brick, with a handsome bar and an impressive rear fireplace (not yet working) and chimney — lives up to its Kings County catechism of “sourcing the finest local and sustainable ingredients possible” and doing interesting things with them.

Start with whiskey bread served with “cultured” butter. “This is cake,” a friend moaned over thick, crunchy crust and rye subtly insinuated into the yeast. It emerges from an underutilized brick oven that once cranked out pizza. The house also uses it to roast vegetables, and McCoy says the restaurant will “eventually use it for some late-night stuff.” Soon, please.

Although relatively short and changing nightly, Hilbert’s menu offers something for everyone. Dreamed up for the neighborhood’s “lots of vegans,” McCoy said, house-made pecan tofu could convert me — it’s lightly sauteed, then flash-sauteed on top for a bit of welcome crunch.

“The best in my life,” declared a friend who subsists on soybean curd. It came with black quinoa and wild spinach in a vivid mushroom broth that pulled it all together.

Attention to detail draws forth intense, primal flavors, and just enough invention makes familiar-sounding main elements new. If baby bok choy always tasted this good, I’d have it all the time. It anchored a refreshing cold salad where cauliflower, grapefruit and feta cheese joined the party.

The kitchen showed its brawn with compelling prime rib-eye “cap,” a richly marbled cut of hay-fed beef from Kansas, fortified with pickled bone marrow. Another night, brining locked in the moisture and game essence of Hudson Valley duck breast as hearty as liver, attended by Brussels sprouts , kumquats and pistachios.

Modestly named “slow-poached egg,” a $12 appetizer, is alone worth a ride on the L train (one block away) or even the BQE — the egg supernally soft at its center, running amid braised pork, cannellini beans properly firm as they rarely are and crisp-baked kohlrabi.

Not everything was in its league. Sea scallops were undercaramelized, Amish chicken unoriginal. Walnut soup wasn’t my cup of tea.

And — blame Manhattan? — desserts run all over the map. Trying-too-hard affairs like tangerine curd with juniper and prunes leave you wondering what to taste first, and less than joyful when you finally decide.

Gwynnett St. is still finding its way. But locals have found the way already — McCoy says 70 percent of customers are walk-ins from nearby.

Unlike artfully underdressed trust funders who clog Bedford Avenue, they’re a truly laid-back bunch, looking delighted to have the restaurant’s mellow vibe in their midst. If there’s any sanity left in the world, they’ll soon have a lot of company.